780042121 has 4 divisors (see below), whose sum is σ = 780192000. Its totient is φ = 779892244.

The previous prime is 780042101. The next prime is 780042163. The reversal of 780042121 is 121240087.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 780042121 - 2⁷ = 780041993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (780042101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66841 + ... + 77638.

It is an arithmetic number, because the mean of its divisors is an integer number (195048000).

Almost surely, 2^780042121 is an apocalyptic number.

It is an amenable number.

780042121 is a deficient number, since it is larger than the sum of its proper divisors (149879).

780042121 is a wasteful number, since it uses less digits than its factorization.

780042121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149878.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 780042121 is about 27929.2341642230. The cubic root of 780042121 is about 920.5329776421.

The spelling of 780042121 in words is "seven hundred eighty million, forty-two thousand, one hundred twenty-one".